This core will provide support for all four projects by performing the animal experiments proposed by each project that utilize different models of experimental colitis. The core's main functions will be: 1) to generate transgenic and knockout and transgenic animals in collaboration with the Mouse Genetics Facility. 2) to genotype and expand lines from transgenic founders and knockouts. 3) to backcross and intercross multiple lines of transgenic and knockout mice. 4) to assist with the experimental colitis models. The Animal Core will take advantage of existing facilities in the Center for Comparative Medicine and Surgery (CCMS) at the Mount Sinai School of Medicine. This is a centralized, shared resource facility that provides veterinary, animal maintenance, and research support to investigators engaged in a variety of research utilizing animal studies. The program is fully accredited by the American Association of Laboratory Animal Care, International. All of the proposed animal experiments will take place in the state-of-the-art barrier facility located on the SC level of the East Building. This is a rodents only facility that offers individually ventilated cages and a fully automated watering system. The Core will provide the technical expertise and support, as well as the necessary equipment and reagents needed for performing all study-related manipulations in mice.